Yes, the route as I showed it, is paved. There may be a section right near Lolo Pass that's hard dirt, but it's certainly rideable the whole loop like that on a road bike with non real problems. This is the exact route that the Barlow Century uses in their charity ride.

Yes, the climb up Last Chance Mountain there looks grueling. After that, not too bad, with a wonderful looking descent.

Files over 20mb require memberships, so I'll see if in the future I can keep them under that.